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how to generate the black bars at top and bottom?

Posted: 15 Jan 2015 16:02
by SarasotaSlim
Ok, let's say I have a video file that is 720 x 480 and has a display aspect ratio of 4:3.

EDITED: [Sorry, I had done an incorrect calc for actual aspect-ratio, so I've removed those statements.]

But, it seems to be a quite common practice for some movie videos to be converted to wide-screen
format, with an aspect ratio of 16:9, with black bars on top and bottom to compensate.

So, here's my actual question:

So, when using VLC (sout) to transcode a video, is there a way to get it to NOT default to producing
the orig aspect-ratio in the input file, but instead produce an indicated 16:9 (by creating the black bars at top and bottom)?

In other words, I want to maintain the original 720x480 resolution, and just change the indicated aspect ratio,
from 4:3 to 16:9.

What cmd-line sout arguments would I use to accomplish that?

[ I thought this would be easy...just to add "--aspect-ratio "16:9" to my cmd-line, but that does NOT
seem to do it. So, what is the correct way, assuming one exists? ]

TIA...

-- Slim

Re: how to generate the black bars at top and bottom?

Posted: 18 Jan 2015 08:15
by Jean-Baptiste Kempf
-Not so sure it's possible.

Re: how to generate the black bars at top and bottom?

Posted: 18 Jan 2015 14:14
by mederi
Perhaps transcoding with canvas or croppadd video filter is what you want.
https://forum.videolan.org/viewtopic.php?f=4&t=112347

Re: how to generate the black bars at top and bottom?

Posted: 18 Jan 2015 15:41
by SarasotaSlim
Perhaps transcoding with canvas or croppadd video filter is what you want.
https://forum.videolan.org/viewtopic.php?f=4&t=112347
Yes, thanks, I too think 'canvas' should be able to do it. 8)

[ I guess I just need to do some experiments with some small snippets, and figure out the details of exactly
what values to try. ]